1. Field of the Invention
The present invention relates to a pedal device.
2. Description of Related Art
JP-A-2007-299137 describes a pedal device to control an operation state of an engine of a vehicle in accordance with a force pressing a pedal arm of the pedal device. The pedal arm is rotatably attached to a housing and is biased by a spring in a direction opposite from a pressing direction of the pedal arm. If the pressing force is increased, the pedal arm is rotated in the pressing direction. If the pressing force is reduced, the pedal arm is rotated in the opposite direction by the biasing force of the spring.
A rotation angle of the pedal arm is detected by a rotation angle sensor that is arranged not to contact the pedal arm. A magnet is attached to the pedal arm, and generates a magnetic field. The rotation angle sensor detects a variation of magnetic flux density that is generated by a direction of the magnetic field. A signal of the detection is transmitted to an engine control unit (ECU) of the vehicle. The ECU controls a fuel injection amount or an air intake amount, for example, based on the detection signal representing the rotation angle of the pedal arm.
The pedal arm passes through an opening of the housing, and has a stopper. When a contact face of the stopper contacts an edge of the opening, the pedal arm is defined to be located at a totally-closed position. The contact face of the stopper is approximately parallel with a plane including a rotation axis of the pedal arm. Thereby, positions of the magnet and the rotation angle sensor are restricted from being deviated in a radial direction with respect to a rotation center of the pedal arm even if a manufacturing tolerance is generated in the edge of the housing and the contact face of the stopper. Therefore, a variation in the signal output from the rotation angle sensor can be reduced when the pedal arm is located at the totally-closed position.
Further, the pedal arm is secured to have play in the opening of the housing while the pedal arm is rotated in the pressing direction or the opposite direction. Therefore, the contact face of the stopper is located to be approximately perpendicular to a gravity direction when the pedal device is mounted to the vehicle. If a foreign matter such as sand is accumulated on the contact face, a gap is generated between the edge of the housing and the contact face of the stopper. In this case, the pedal arm cannot return to the totally-closed position even when a driver of the vehicle does not press the pedal arm.
While the vehicle is braked, if the pedal arm does not return to the totally-closed position, the signal indicating the totally-closed position is not output from the rotation angle sensor to the ECU. The ECU keeps the operation state of the engine in accordance with a rotation angle of the pedal arm. In this case, an unintentional controlling of the engine may be performed.